Surgery in the abdomen is presently performed through an incision that permits access to the operative site (laparotomy), or through rigid cannulas inserted into small incisions in the abdominal wall as visualized by a camera (laparoscopy). There is no reliable device or method for sewing or stapling through a flexible endoscope. Such procedures are primarily diagnostic in nature with the exception of biopsy and polypectomy. Recently there has been increasing interest in devising methods for performing surgery via the flexible endoscope inserted through a natural orifice. The potential advantages that such procedures might offer are related to their being even more minimally invasive than laparoscopic surgery, decreasing morbidity and discomfort. This scenario would be especially advantageous in the morbidly obese patient, who presents an even larger operative challenge than a patient of normal weight. In addition, if such procedures were made possible, certain operations to treat morbid obesity performed through a natural orifice may become possible.
Morbid obesity has reached epidemic proportions in the United States, affecting more than 30% of adults. The prevalence of obesity has been rising steadily, resulting in significant chronic health problems and nearly 300,000 deaths per year. Obesity and its associated health problems have substantial economic consequences for the United States health care system; in 1995, the total costs attributable to obesity were estimated at $99 billion. Bariatric surgery is the most effective treatment modality, and has been recognized by the National Institutes of Health as the only successful long-term treatment.
The Roux-en-Y gastric bypass operation considered the standard of surgical care, is a long and risky operation whether performed laparoscopically or through laparotomy. Because of the increased risk entailed in this operation, gastric restrictive operations have been performed in increasing numbers. These operations are intended to restrict food intake without removing any gastric tissue, or bypassing intestine. While less traumatic, significant convalescence time and complications still prevail.
Providing a method and accompanying device for performing surgery in conjunction with a flexible endoscope may reduce the length and complexity of abdominal operations, possibly decreasing morbidity and mortality, shortening hospital stay, and providing cost savings.
Transgastric surgery has been attempted, but has not yet been successful in humans, primarily because there is no reliable device to enable closing of the incision through the flexible endoscope. If this were to be made possible, instruments could be introduced through a natural orifice, for example the mouth, and then brought through an incision in the stomach. In this way surgery could be performed in the abdominal cavity eliminating necessity for external incisions.
Conventional surgery often necessitates the use of clips, staples, or other surgical fasteners. Such procedures generally require that an extensive incision be made (open surgery), or that a series of small incisions be created, through which several cannulas are placed for providing access to a body cavity (laparoscopic surgery).
Currently, there is no reliable method for securing clips, staples, or other surgical fasteners inside a patient's body in conjunction with a flexible endoscope. The challenge entailed in creating a fastener and a delivery and deployment device that may be passed through a flexible endoscope is two-fold: firstly, the working channel of an endoscope is very narrow requiring a device with an outer diameter sufficiently small to pass through it. Secondly, a flexible endoscope bends along with curvatures of the internal body lumens, requiring similar flexibility of a fastener delivery and deployment device to enable such a journey. Both of these challenges have not yet been surmounted; hence there are no such devices currently available. Suturing operations have similar limitations, and as such physicians have been unable to perform surgical procedures via natural body orifices using a flexible endoscope.
When performing a procedure with an instrument passed through a flexible endoscope, the simplest method to operate this instrument is through either a pushing, or pulling motion performed proximally by the operator. As the surgical instruments traverse bends in the endoscope, a turning or torquing motion performed proximally does not translate in a 1:1 ratio distally. Pushing or pulling, on the other hand is ergonomically simpler for the operator, and is transmitted through the entire instrument better. Therefore, most procedures performed through the flexible endoscope, such as biopsy, or polypectomy, employ a push or a pull action at the handle, or proximal aspect of the instrument. It would therefore be advantageous to provide a device that would enable application of fasteners through a simple push of the extracorporeal, proximal aspect of the fastener application device.
Laparoscopic surgery has been developing rapidly in the past few years because it is less invasive than open surgery. These procedures enable sewing or stapling tissue via a series of small abdominal incisions through which a number of cannulas are placed. Rigid instruments are passed through these cannulas and manipulated from outside the body. The surgical procedure is visualized with a camera, which is introduced through a separate cannula.
Providing smaller diameter instruments capable of reaching surgical sites through smaller access ports or cannulas would provide an advantage during laparoscopic surgery because smaller incisions cause a lesser injury, providing for a more rapid healing process. The size of the instruments used to deliver surgical staples, for example, is dictated by staple size.
The currently used staple delivery device sizes have been decreased by designing the device for delivery of a closed staple. This enables passage of these devices through smaller diameter cannulas. Upon reaching the operative site, such a staple must be opened by some means, in order to engage a target tissue, after which the staple is again closed upon the tissue. Consequently, a staple may be displaced, or slip out of the delivery device's jaws. Furthermore, the force required to open and close the staple or clip is magnified because it is transmitted through the distance of the shaft. Providing an anchoring system that would permit introduction and delivery of an anchor in a substantially closed configuration, would preclude a need for the “closed open closed” design.
Although there appear to be no commercial devices on the market that enable stapling through the working channel of the flexible endoscope, U.S. Pat. Nos. 5,222,961, 5,156,609, 5,015,249 and 5,049,153 to Nakao et al. describe various embodiments of an endoscopic stapling device. U.S. Pat. No. 5,015,249 describes a flexible stapler whereby the staple is configured with an open bias, and releasably connected to a rod member. The staple is ejected by pushing the rod member forward. Upon engagement of the staple with tissue, the staple being opened by its open bias, a tubular member is pushed over the staple to close it. The problem with the embodiment of the '249 patent is the following: bowel wall thickness, for example, is approximately 0.5 cm, and its consistency is slightly firmer than that of a calfs liver. Closing an indwelling staple by pushing a tubular member over it may push the entire staple through the bowel wall.
U.S. Pat. No. 5,049,153 describes a flexible stapler, wherein a staple with an open bias is disposed in the prefiring position inside said stapler's open jaws. The stapler is brought to the tissue with the indwelling staple, closed upon the tissue, and once the staple locks, the staple legs are released. U.S. Pat. No. 5,156,609 describes a plurality of second staples each having a spring bias. U.S. Pat. No. 5,222,961 describes various additional means of locking a staple. All the above-mentioned patents address staples to be delivered by an endoscopic stapler. The invention disclosed herein describes an anchoring device and an instrument for delivering one or more anchors held together by a suture thread or another line element. This device assembly is designed quite differently than the staplers described above.